The problem is the stock market is somewhat disconnected from reality.
I need to elaborate this further because now it just seems to be some anti-capitalist snark (which I do not want it to be).
The way stocks were supposed to work is that you buy a part of a company keep it and make money by getting a part of their profits every year (called dividend). Todays problem is that we want to make more money, faster (which is not "wrong" intrinsically as some people might think, but it does not work with the "traditional" stock model). The reason it does not work is that it may take some time for a company to be profitable and even then they may want to keep some of their profits to invest in research etc. which keeps dividends small (sometimes even 0). The new way one tries to make money is to buy a stock while hoping to be able to sell it to someone else for more money in the future (nothing wrong about that either). The real problem is that this price is based on supply and demand/perceived value which might differ significantly from the actual value (worth of the company's physical assets, paid dividends, ...) - it is easier to see these differences on more tangible things like luxury watches, art, etc., which are nowhere priced for their physical value (a frame and some paint - does not seem to be worth much ...) but they are there for stocks, too.
Now to the "hyper efficient"-part: yes, that's true, the market is hyper efficient, as in it is not that easy to get money out, because that would mean that someone else leaves it on the table, but everything still happens in the "perceived value" point of view, in which you would have to compete, too, to make money with stocks.
The dilemma in which CEOs find themselves is that not all actions that are good for the company itself are good for the perceived value/stock price, at least not when you are forced to do "short-term thinking" (the CEO keeping his job, the trader making money now).